Make broken JSONOBject.NULL.equals(null) consistent with Objects.hashCode(null)

Bug: 28189207
Change-Id: I76b8cc270dbf1b63f43c0dcd6970a703ad040da4

2 files changed, 10 insertions, 0 deletions

diff --git a/json/src/main/java/org/json/JSONObject.java b/json/src/main/java/org/json/JSONObject.java
index 9ea91a6a11..7902389794 100644
--- a/json/src/main/java/org/json/JSONObject.java
+++ b/json/src/main/java/org/json/JSONObject.java
@@ -21,6 +21,7 @@ import java.util.Collection;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 
 // Note: this class was written without inspecting the non-free org.json sourcecode.
@@ -100,6 +101,8 @@ public class JSONObject {
         @Override public boolean equals(Object o) {
             return o == this || o == null; // API specifies this broken equals implementation
         }
+        // at least make the broken equals(null) consistent with Objects.hashCode(null).
+        @Override public int hashCode() { return Objects.hashCode(null); }
         @Override public String toString() {
             return "null";
         }
diff --git a/json/src/test/java/org/json/JSONObjectTest.java b/json/src/test/java/org/json/JSONObjectTest.java
index 9029ec6c6c..07d1cf6439 100644
--- a/json/src/test/java/org/json/JSONObjectTest.java
+++ b/json/src/test/java/org/json/JSONObjectTest.java
@@ -27,6 +27,7 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.NoSuchElementException;
+import java.util.Objects;
 import java.util.Set;
 import java.util.TreeMap;
 import junit.framework.TestCase;
@@ -825,6 +826,12 @@ public class JSONObjectTest extends TestCase {
         assertTrue(object.isNull("bar"));
     }
 
+    public void testNullValue_equalsAndHashCode() {
+        assertTrue(JSONObject.NULL.equals(null)); // guaranteed by javadoc
+        // not guaranteed by javadoc, but seems like a good idea
+        assertEquals(Objects.hashCode(null), JSONObject.NULL.hashCode());
+    }
+
     public void testHas() throws JSONException {
         JSONObject object = new JSONObject();
         object.put("foo", 5);